Shutter mounting for ventilating duct outlets



1951 R. v. PFAUTSCH SHUTTER MOUNTING FOR VENTILATING DUCT OUTLETS FiledAug. 4, 1949 IN VEN TOR: 144M,

ATTORNEYS.

Patented Dec. 18, 1951 s PATENT OFFICE SHUTTER MOUNTING FOR VENTILATINGDUCT OUTLETS j Raymond V. Pfautsch; Chicago,

I Ilg Electric Ventilating Company,

a corporation of Delaware Ill., assignor to 1 Chicago, Ill., 1

Application August 4, 1949, Serial No.l108,5,96

, 1 I I 4 Claims. (Cl. 98-116) 1 Thern'ain o jects of vide an improvedform and arrangement of a shutter mounting for a ventilating ductoutlet;

to provide an improved arrangement of means for yieldingly biasing saidshutter toward open this invention are topr or closed position dependingupon whether or not air is being exhausted through said duct,wherebysaid shutter constitutes a minimum obstruction to the exhaust ofairwhen a'ventilating fan is in operation, but'providescomplete weath-'erftight protection when the I idle; and to provide an improved shuttermounting andbiasing means of this kindwhichis'economic'al tomanufacture, easy to install, and positive in operation.

In'the. accompanying drawings:

' Fig. 1 is a fragmentary sectional view through aceiling and outsidewall'showing in side elevation a ceiling ventilator andceiling-concealed duct, for use with which an outlet shutterco'nventilating fan is structed linaccordance with this invention has"been designed;

Fig. 2 isan-enlarged front elevation of a ven,

jtilating-duct outlet-box equipped with a shutter mounting-constructedin; accordance with this inventiornthe viewbeing takenfrom theright handend of Fig. 1-; .7 :Fig. :3 is anenlarged cross-sectional,,view ,of thesame taken on the line 3-3 of: Fig. 2 showing the shutter in itsnormally close'd position; '1.

- Fig. 4 is a similar view showing-the shutter in the idleness'oroperation of of the air-to hold the shutter connected by a ceilinconcealed duct 'lleadingto an outlet box or hens-1 ing "8 whereinis'lmountede shutter '9 for" the purpose of keepingtlie duct 1* closed whenthe ceiling fan Bis not in operation. 1

Thefan 6 may be of' any desired construction and appropriately mountedin the ceiling!!! of theroom whichis to ,be ventilated by exhausting airtherefrom through the duct 1.

The duct 1 may be of conventional sheet metal or some other material,concealed within the ceiling in and'connecting an elbow ll, wherein thefan 5 is mounted, with is equippedgwith thisf'improved shutter 9.

The outlet box 8, in its over-all dimensions, is somewhat larger thanthe duct 1 ;tegral -sle eye part l2 which. telescopes with the endof-the main duct 1 andconstitutes theoutlet l3 for said duct 1. Thisoutlet box-8 ,is' set the outlet box 6 which and has an ini io itheleiis q iv illli @iitt t pa a.

5 *"A fiash' cap 1 51s mounted along the upper edge of the box 8 anddisposed at an incline so as to prevent as much-as possible the entranceof rain into the box 8. 'A grating it, formed of rods connectedto'angle'bars, is attached to the front of the box 5 by means of screwsI! and prevents birds, squirrelsor other animals from" acquiring accessto the box 8 or duct 1.

The-improved forin'of shutter 9 for the duct outlet l3 comprises a framelfi whereon is hinged a :door' l9 to which is attached a spring 20 tobias the door'tow'ard a closed or open position depending upon whetherornot the fan 6 is operating to exhaust air through the duct "I; The frame13 is a rectangular stamping with a transverse flange 2| definingan"openingfco extensive with i l '7 thesleeve l2,

I I The frame l8 mounts a pair of lugs 22 and 'abracket' 23, on theformer of which is hinged the door 19 and to the latter of which isconnected one end of the spring 20. The lugs 22 arebonded adjacenttheupper corners of'th'e frame l8, whereas the bracket 23 is bonded toone of the lower corners of the frame lii The bracket}?! isprovided withan opening' in the form of a notch through which one end of the springZillis looped. j The door l9, asherein shown, comprises a pair'of plates25 and 26 between whichis interposed a sheet of material-i1.

' The plate 25'is formed of a light-weight material, preferably acomposition having a mini mum capacity for heat conduction. The 'aim isto reduce as 'much as possible heat dissipation through the duct 1when'the fan is idle, The plate 25 is of a dimension practically thesame as the outside dimension 'of the flange 2| of the frame [8.

1 The sheet 2? is preferably of a relatively soft material, such asfelt, and is used to provide the best possible seal around the perimeterof the flange 2| cf the frame l8 when the door I9 is closed. This sheetof material 21 is heldto ,plate 2 5,,.' as a matterv of fact, thesealingof the door l9 against the fian'geZl could be efiect'ed as well,by a rectangular ring 7 or gasket held in place by alrectangularfring,riveted to .the plate the duct outlet '13 at" the end or.

edge of the plate 25 by hinge pads 29. The ends of the .shaft 28 extendbeyond the lateral edges of the plate 25 to serve as trunnions forswingably mounting the door l9 on the lugs 22. The journaling of theshaft 28 on the lugs 22 is such that when no exhaust is being dischargedthrough the duct 1 gravity tends to swing the door into a verticalposition, as shown in Fig. 3, thus bringing a perimetrical area of thesheet 21into contact with the perimeter of the flange 2| of the frameI8. A crank 39 is secured to one end of the shaft 28 so that the axis ofthe pin 3| is oifset from the plane of the door plate 25 slightly morethan is the axis of the shaft 23, as will most clearly appear from Figs.3 and 4.

p The spring is connected at one end to the lug or bracket 23 on theframe I8 and at the other end to the crank pin 3|. Thus, the axis of thespring 20 is disposed transversely to the axis of the shaft 28 in aposition on one side or the other of the axis of the shaft 28 dependingupon whether the door I9 is in its open or closed position. Such anarrangement of the spring 20 provides a form of toggle so that thespring 20 serves to supplement the action of gravity when there is noexhaust passing through the conduit 1 to secure the door in its closedposition, as shown in Fig. 3. However, as soon as there is an exhaust ofair passing through the conduit 1, the spring 20 will supplement theforce of such draft and tend to hold the door in its open position asshown in Fig. 4.

The operation of this improved shutter mechanism is believed to beapparent from the foregoing description.

Variations and modifications in the details of structure and arrangementof the parts may be resorted to Withinv the spirit and coverage of theappended claims.

I claim:

1. A shutter for a ventilating-duct outlet comprising, a frame having anopening coextensive with said duct outlet, a plate, trunnions on theupper corners of said plate journaled on said frame so that gravitytends to swing said plate to a vertical'position to close said frameopening when no air is being discharged through said duct, an eccentriccrank pin connected to one of said trunnions and offset fromv the. axisof said trunnions, and a spring connected at one end to said crank pinand at the other end to said frame at a point below said crank so as todispose the axis of said spring transverse to the axis of said trunnionson respectively opposite sides thereof when said plate is in its openand closed positions, said spring thereby supplementing the action ofgravity to hold said plate in vertical position to close said outletwhen no air is being discharged through said duct and supplementing theforce of air being discharged through said duct to hold said plate inopen position.

frame at a point below said crank pin so as to dispose the axis of saidspring transverse to the axis of said shaft, and on respectivelyopposite sides thereof when said plate is in its open and 1 closedpositions, said spring thereby supplement- 2. A shutter foraventilating-duct outlet comprising, a frame having an openingcoextensive with said duct outlet, lugs extending transversely outwardfrom said frame adjacent the upper corners, a plate, a shaft fixed alongone edge of said plate and having the ends of said shaft extended beyondthe ends of said plate to serve as trunnions journaled on said lugswhereby said plate is swingably mounted so that gravity'tends to swingsaid plate to vertical position to close said frame opening when no airis being discharged through said duct, an eccentric crank pin conmg theaction of gravity to hold said plate in closed position when no air isbeing discharged through said duct and supplementing the force of airbeing discharged through said duct to hold said plate in open position.

3. A shutter for a ventilating-duct outlet comprising, a frame having atransverse flange defining an opening coextensive with said duct outlet,lugs extending transversely outward from said frame adjacent theuppercorners thereof and beyond the edge of said flange, a bracket atthe lower end of said frame extending transversely outward therefrom andhaving an opening therein located inwardly of the edge of said frameflange, a plate, trunnions on the upper corners of said plate journaledon said lugs whereby gravity normally tends to swing said plate tovertical position to contact the edge of said frame flange to close saidframe opening when no air is being discharged through said duct, aneccentric crank pin connected to one of said trunnions and ofiset fromthe axis of said trunnion outwardly of the plane of said plate, andatension spring having one end connected to said crank pin and the otherend connested throughsaid bracket opening so as to dispose the axis ofsaid spring transverse to the axis of said trunnions and onrespectivelyopposite sides thereof when said plate is in its open andclosed positions, said spring thereby supplementing the action ofgravity to hold said plate in vertical position to close said frameopening when no air is being discharged through said duct andsupplementing the force of air being discharged through'said duct tohold said plate in open position.

4. A shutter for a ventilating duct comprising an angle bar frame havinga vertical flange for attachment to the duct and a horizontal flangedefining the outlet opening of the duct, a plate normally disposedvertically in contact with said horizontal flange for closing saidopening, means on said frame for hingedly supporting said plate on ahorizontal axis above said opening, and an upright tension spring havingits lower end connected to said frame and its upper end connected tosaid plate at a point above said horizontal axis and outwardly of theplane of said plate, said REFERENCES cI'rEn The following references areof record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,915,994 Harnett June 27, 19332,279,425 Voysey Apr. 14, 1942 2,299,832 Mader Oct. 27, 1942 2,355,836Willey Aug. 15, 1944 Schrum Apr. 25. 1950

